Table 2 Summary table showing the hazard ratios from Cox regression analyses for the three IPI models, baseline IPI, rIPI1 and rIPI2

Low-risk IPI

(score 0/1)

Reference

Reference

Reference

Low-intermediate IPI

(score 2)

2.0 (0.61, 6.76)

p = 0.248

1.56 (0.54, 4.51)

P = 0.4

1.8 (0.5, 6.0)

P = 0.3

High-intermediate IPI

(score 3)

7.6 (2.61, 22.36)

p < 0.0001

5.32 (2.14, 13.22)

P < 0.0001

6.4 (2.2, 18.6)

P = 0.001

High-risk IPI

(score 4/5)

8.9 (2.94, 27.17)

p < 0.0001

6.9 (2.61, 18.32)

P < 0.0001

8.1 (2.7, 24.6)

P < 0.001